OBJECTIVE: To determine whether the gestational age at the time of prenatal androgen exposure contributes to the altered glucose/insulin dynamics in female rhesus monkeys, as part of a study investigating the etiology of polycystic ovarian syndrome (PCOS). RESULTS Female rhesus monkeysexposed to androgen early in gestation had a significantly lower percentile for the relationship between insulin sensitivity and acute insulin response (10.3 q 7.0 %; p < 0.01) compared to the late treated androgenized females and control females (40.5 q 7.2 % and 31.3 q 6.0 % respectively). This result indicated that early exposed androgenized females have reduced pancreatic b-cell response relative to their insulin sensitivity. Overall, these findings suggest that prenatal androgen excess during early gestation exerts a significant adverse effect on pancreatic b-cell function in adulthood. Two of these androgenized females have since become glucose intolerant. Prenatal androgen excess in females may, therefore, pose a risk of early development of diabetes in adulthood. FUTURE DIRECTIONS We plan to explore the role of prenatal androgen excess in causing pancreatic impairment in female rhesus monkeys and examine potential mechanisms. KEY WORDS testosterone, diabetes, pancreas, polycystic ovarian syndrome, insulin, glucose. UW Graduate School Research Committee, UW Medical School Committee